All of the ideals of Hindu wisdom can be summarized into one word: ahimsa. Nonviolence is an ancient principle of Hinduism. Hindus are known to be peace-loving, and India is possibly the only large nation to not have had any colonial conducted war campaigns despite its great wealth. Even the Indian independence movement to free it from British colonial power was uniquely and successfully conducted in a nonviolent manner.
Ahimsa is the Hindu belief that symbolizes love, genuine care, and compassion towards all living beings. The principle of ahimsa extends far beyond avoiding causing physical harm; it also includes avoiding causing harm through speech and thought. Ahimsa is non-injury in mind, speech, and action towards any creature. Specifically:

In Mind – not to think maliciously of others.

In Speech – not to use foul language, swear, backbite, or quarrel.

In Action – avoid injury to any person or creature.

The Swaminarayan faith, like most branches of Hinduism, is non-proselytizing—it does not believe in using force for religious ends. Other than defensive purposes, the use of weapons is discouraged. Bhagwan Swaminarayan preached this principle of ahimsa to His followers and asked them to conduct their lives peacefully with respect and love for all. In the Vachanamrut Gadhada I-69, He explains that in order to attain moksha, one should practice ahimsa dharma.

There are many reasons why Hindu Dharma strongly advocates ahimsa. Hindus believe that Bhagwan pervades all living and non-living things. Bhagwan pervades humans, animals, plants, mountains, and the whole of creation; hence, all life is sacred and should be loved and revered. In addition, the law of karma teaches that whatever we do through word, thought, and deed will return to us whether it is in this life or the next. If we cause harm in any way, it will eventually revert back to us in an equal or amplified intensity.